• Korean Journal of Food Science and Technology
• /
• v.15 no.2
• /
• pp.177-182
• /
• 1983

Direct conversion of starchy materials to single cell protein of Sporobolomyces holsaticus FRI Y-5 was investigated. Effect of yeast extract concentration on its cell growth showed that it could utilize more of starch in the medium containing 2.5 g/l of yeast extract. In case of jar fermentor culture, the specific growth rate and cell yield of Sp. holsaticus on soluble starch were calculated to be $0.14\;hr^{-1}$ and 0.425, respectively and its maximum cell concentration was 13.4 g/l. After 80 hr of incubation time, 45.96% of starch was consumed and 45.1% of relative blue value was decreased. Reducing sugars in the starch medium seemed to increase from 4.06 g/l to 6.08 g/l and then to decrease. During fermentor culture, pH of medium was almost not changed in the range of $pH\;7.0{\pm}0.5$. The optimal temperature and pH of Sp. holsaticus amylase activity were $40^{\circ}C$ and pH 7.5, respectively. It was shown from the effect of Tapioca starch concentration on the cell growth that the optimal concentration of Tapioca starch for Sp. holsaticus was lower than that of soluble starch. FRI Y-5 cells settled much slower than Sp. holsaticus IFO 1032 cells and the viscosity vs cell concentration relationship was related to be linear.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.8
• /
• pp.1105-1113
• /
• 2015

Bokbunja (Rubus coreanus) is a Korean fruit and wild black raspberry that has antioxidant, anticancer, and beauty effects due to its abundant polyphenols and anthocyanins. The purpose of this study was to investigate the blood flow improvement effect of Bokbunja seed oil (BSO) in a high-fat diet-fed mouse model. We examined improvement of blood flow and its related biomarkers in vivo. Mice were divided into four groups; Control, high fat diet control (negative control, HFD), salmon oil control (positive control, HFD+commercial n-3 fatty acid), and BSO experiment groups (HFD+2 g/2,000 kcal, HFD+4 g/2,000 kcal). After the mice were sacrificed, plasma triglyceride, cholesterol, and blood flow-related biomarkers (coagulation factor 7, 12, serotonin, TXB2, PT, and aPTT) were measured in mouse blood and organs. BSO reduced blood viscosity through improvement of blood lipids (cholesterol and plasma triglycerides) as well as levels of blood coagulation factors and blood platelet activity. BSO also delayed blood coagulation time. Thus, we confirmed that BSO inhibits excessive blood clotting of blood vessels and improves blood flow. Taken together, these results suggest that BSO decreases plasma triglycerides and cholesterol and improves blood flow by regulating biomarkers.

• Fire Science and Engineering
• /
• v.34 no.2
• /
• pp.147-155
• /
• 2020

This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.

• Journal of the Korean Geotechnical Society
• /
• v.36 no.11
• /
• pp.149-156
• /
• 2020

Permeation grouting effectively enhances soil strength and decreases permeability of soil; however, the flow of grout is heavily affected by anisotropy of hydraulic conductivity in layers. Therefore, this study investigates the effect of permeability anisotropy on the effective radius of horizontal permeation grout using computational fluid dynamics (CFD). We modeled the horizontal permeation grout flow as a two-phase viscous fluid flow in porous media, and the model incorporated the chemical diffusion and the viscosity variation due to hardening. The numerical simulation reveals that the permeability anisotropy shapes the grout bulb to be elliptic and the dissolution-driven diffusion causes a gradual change in grout pore saturation at the edge of the grout bulb. For the grout pore saturations of 10%, 50% and 90%, the horizontal and vertical radii of grout bulb are estimated when the horizontal-to-vertical permeability ratio varies from 0.01 to 100, and the predictive model equations are suggested. This result contributes to more efficient design of injection strategy in formation layers with permeability anisotropy.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.5
• /
• pp.629-638
• /
• 2016

In this study, the effect of inorganic constituents on the physicochemical properties of pyrolytic products produced from empty fruit bunch (EFB) by fast pyrolysis were investigated. Inorganic constituents were removed from the EFB by means of washing treatment with hydrofluoric acid (HF) and distilled water (D.I water). Ash content decreased from 6.2 wt% (EFB) to 2.4 wt% (HF-EFB) and 3.5 wt% (D.I-EFB), respectively. As a result of the inorganic component, a quantity of potassium in EFB has showed the highest removal efficiency in both HF and D.I water (HF: 80.3%, D.I water: 72.8%). Fast pyrolysis was performed with demineralized EFB in the fluidized bed reactor under the temperature of $500^{\circ}C$ at the residence time of 1.3 sec. The yield of bio-oil was determined to 57.3 wt% for HF-EFB and 52.1 wt% for D.I-EFB, respectively. Biochar yield decreased whereas yield of non-condensable gas increased with decreasing inorganic content of EFB. Water content decreased from 26.9% (EFB) to 9.9% (HF-EFB) and viscosity increased from 16.1 cSt (EFB) to 334 cSt (HF-EFB).

• Korean Journal of Food Science and Technology
• /
• v.23 no.4
• /
• pp.485-489
• /
• 1991

In order to study the effects of blanching and germination of soybean on the quality of soymilk, the soybeans were differently treated as follow; (1) blanched for 5 min at $100^{\circ}C$, (2) germinated for 2 days at $25^{\circ}C$, (3) germinated for 2 days and then blanched for 5 min at $100^{\circ}C$. The qualities of various soymilks prepared from the treated soybeans were compared with those of soymilk from the untreated soybeans. Blanching of soybeans decreased yields, solid materials, viscosity, total protein, soluble nitrogen, and total sugar of soymilk but no effect on its free sugar contents, specific gravity, and pH. The blanching, however, improved the sensory properties and decreased the n-hexanal contents of soymilk to about 1/2.4. Germination of soybeans improved the yields, physical, chemical, and sensory properties and decreased the n-hexanal contents of soymilk to about 1/5. The germination plus blanching of soybeans showed kind of combined effects of germination's and of blanching's, resulting in the decrease of n-hexanal to about 1/10 and improvement in sensory properties of soymilk.

• Food Science and Preservation
• /
• v.12 no.6
• /
• pp.572-577
• /
• 2005

This study was conducted to investigate the effect of binding agents on the physicochemical characteristics of granule prepared by Lentinus edodes. The mushroom powder was mixed with com starch, lactose, gelatin, gum arabic, or dextrin(DE=23), and the mixtures were passed to granule sieve. Solubility of granule was in the following order, gum arabic>gelatin>lactose, dextrin>corn starch. L value was in the following order, com starch, lactose>gelatin, gum arabic, dextrin. a value and pH were not affected by the binding agents. b value was in following order, lactose, corn starch>gelatin, gum arabic>dextrin. Viscosity was in the following order, gelatin, corn starch>gum arabic, dextrin>lactose. Water absorption was in the following order, gelatin>lactose>corn starch>dextrin>gum arabic. Sugar content was in the following order, gum arabic>lactose, dextrin>corn starch, gelatin. Protein content was the highest in granule formed with gelatin. These results suggested that gum arabic can be utilized for improving solubility and lowering absorption of Lentinus edodes granule as binding agent.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.30 no.4
• /
• pp.150-155
• /
• 2020

Alumina (Al₂O₃) is mainly used as a structural ceramic material and to have good mechanical properties requires a dense microstructure. In commercial fabrication, the liquid phase sintering process is adjusted to reduce the sintering temperature of alumina. In this study, the effect of added amounts of cobalt oxide as a coloring agent on the microstructure and mechanical properties was investigated in the CaO-SiO₂-MgO-system liquid phase sintering of 92 % alumina at various sintering temperatures. When 11 wt% Co₂O₃ was added, a rearrangement of alumina particles, which is the main densification step in liquid phase sintering, occurred from a sintering temperature of 1200℃. Solution re-precipitation and coalescence steps followed from 1300℃ with the grain growth of alumina particles. The addition of excess Co₂O₃ and sintering temperatures above 1400℃ resulted in a decrease in sintered density and Vickers hardness, because of the low viscosity of the liquid phase. In 92 % alumina with the addition of 11 wt% Co₂O₃, a sintered density and Vickers hardness of 3.86 g/㎤ and 12.32 GPa, respectively, were obtained at a sintering temperature of 1350℃.

• Journal of the Korea Concrete Institute
• /
• v.14 no.5
• /
• pp.742-749
• /
• 2002

This study was performed to clarify the formation procedure of continuous voids in cellular concrete, and to examine the effect of a foaming agent on the manufacture of cellular concrete with continuous voids. By the experiments, it was determined that cellular concrete to be formed with continuous voids is influenced by temperature, viscosity and flowability of cement paste, and stability of air voids, and is formed in accordance with cohesion of air voids. It was also found that separate voids are formed at an added amount of air voids corresponding to 2 ％ or less of the amount of cement, whereas an antifoaming phenomenon occurs when the added amount of air voids exceeds 9 ％ of the amount of cement. In products with respective cement fineness of 3,000, 6,000, and 8,000㎠/g, a higher compressive strength was exhibited at a higher cement fineness. The continuous void ratio depending on a variation in fineness was 38 ％, 52 ％, and 22 ％ in those products, respectively. That is, a highest continuous void ratio was exhibited at a cement fineness of 6,000㎠/g. When the water-cement ratio was reduced from 45％ to 25％, the compressive strength of the cellular concrete was increased from 15 kgf/㎠ to 20 kgf/㎠ Thus, the reduction in water-cement ratio was effective in achieving an increase in strength without any variation in the specific gravity of the cellular concrete.

• KSBB Journal
• /
• v.16 no.5
• /
• pp.516-522
• /
• 2001

The large-scale production of antibiotics by filamentous mycelial organism requires and adequate supply of dissolved oxygen. In terms of productivity, it means that oxygen transfer is the rate-limiting step. Therefore, the oxygen transfer coefficients(K$\_$L/A) were determined in a broth involving a filamentous mycelial organism such as Streptomyces avermitilis for use in fermentations. To determine (K$\_$L/A) inn a stirred vessel, a great deal of effort is required to provide all the cells with a sufficient oxygen supply. To overcome the oxygen limitation in a batch culture, a fed-batch culture was applied to control the growth rate by an intermittent supply of nutrients. Thus, it was possible to maintain a suitable dissolved oxygen concentration at a low agitation rate. The optimal agitation speed was 350 rpm at low cell concentrations (below 7 g/L) by considering the efficiency of agitation and shear stress. The (K$\_$L/A) was found to decrease from 64.26 to 29.21h.$\^$-1/ when the biomass concentration was increased from 9.82 to 12.06 g/L. In addition, and increase in viscosity was also observed during the growth phase. By comparing the (K$\_$L/A) values for the various agitation and aeration rates, it was found that the effect of an increase in (K$\_$L/A) by aeration was reduced dramatically at high biomass concentrations. However, this effect was not observed when altering the agitation rate. This suggests that controlling the dissolved oxygen concentration by altering the agitation rate was more efficient than increase the aeration rate.